The developed market economies exploit 'the price mechanism' being assisted by the operation of various institutional instruments and measures which rather support and complement the regulatory role of the neoclassical price system than limit the influence of the market. A specific form of the mutual interplay of competitive and cooperative relations is the concept of clusters. The article attempts to reconstruct the most important elements of this concept in relation of the economic role of clusters to the theory of regulation. We present the origins and the relevant definitions of clusters, their attributes and typologies, as well as the criteria of their identification. The results of our enquiries seem to support the thesis that the concept of clusters can be regarded as an important complement of neoclassical economic theory and as an extension of the new institutional economics thanks to the introduction of another dimension, viz. of the element of trust.